Carbapenem antibiotics are a type of β-lactam antibiotics developed in 1970s. Carbapenems attract a lot of attention for the broad antibacterial spectrum, potent antibacterial activity and stability towards β-lactamase. The structural features of carbapenems include: the sulfur at 1-position of the parent core of penam is replaced by a carbon atom, a feature that activates the β-lactam antibiotics by ring strain introduced by the fused five-membered ring; a double bond is introduced at 2-position, which activates the antibiotics by the delocalization of the β-lactam nitrogen lone pair into a conjugated double bond system; a hydroxyethyl group side chain at 6-position is trans-configuration.
The compounds of formula (a) were disclosed in EP0126587. The preferred compounds disclosed therein included the meropenem as shown by formula (b). Meropenem was an antibacterial agent.

Meropenem has been commercialized in many countries. It has excellent antibacterial activity against both Gram positive and negative bacteria. It can be used to treat celiac infection, skin infection and skin soft tissue infection and so on. It exhibits good stability to renal dehydropeptidase-I (DHP-I), yet has a relatively short half life. Meropenem is administered every eight hour.
Because of the overuse of antibiotics, more and more drug-resistant bacteria appear in clinic. It is important to develop new carbapenem antibiotics with excellent antibacterial activity against the various common pathogens causing nosocomial infections and long half life.